Matilda saw better than he did, so most of the activity in his visual centre was bleed-over from her. Fleeting impressions, like the hypnogogic imagery preceding sleep, flitted across the projection screen of his mind. As with smell, the translation was too imprecise to result in anything immediately recognisable, although he kept getting the impression of bulky, rounded forms a chopped up, reshuffled and disturbingly amorphous, like a cubist's idea of elephants.

Geoffrey closed his eyes, blocking what little extraneous input was now reaching them. He concentrated on a particular mental puzzle: holding an Escher figure in his mind, the Meta Presence triangle, and then rotating it, all the while trying to keep the details in sharp focus. It required an intense conscious effort, and because the exercise drew on his mind's visual machinery, it elicited a response in the neural map of his own brain, still hanging there in the upper-left corner of his visual field. His visual cortex was glowing, as bloodflow and neurochemical markers signalled a concentration of resources.

It required an even greater effort to hold the Escher figure in mind and also track the neural changes in the side-by-side scans, but he had trained for that, over and over, until he was capable of making the rapid attentional shifts that allowed him to both perform the concentration exercises and monitor their effects.

Now it was paying off: Matilda's visual cortex was beginning to light up as well, in response to his own. He had no idea what that felt like to her, but she couldn't be experiencing that level of stimulus without feeling something. For a moment, he too felt the rising potential as the visual response he was generating in her began to spill back into his head. It died down just as quickly, though: he had installed dampening protocols to guard against that kind of positive feedback.

He stopped holding the Escher figure in his head and opened his eyelids again. Their minds had returned to quiescence, with no exceptional activity in either visual cortex.

Geoffrey didn't doubt that the link had worked as intended, and that the observed response would be repeatable. He'd done nothing that broke the laws of physics, just wired two minds together in a particular way. It would have been strange if it hadn't worked.

Time to try something else.

Geoffrey did not care for scorpions. He had trodden on one as a child a it had found its way into his shoe one night a and the memory of that lancing, electric pain as the venom touched his nervous system was no less sharp the better part of thirty years later. He had learned to overcome his fear a it would have been difficult to function otherwise, when there were so many other things that could sting and injure a but that childhood incident had imprinted a deep-seated phobia that would be with him for the rest of his life. He'd had occasion to curse that fear, but at last it was going to do something for him instead.

Merely thinking about the scorpion was enough to bring on unpleasant feelings, but now he forced himself not just to return to the incident, but to imagine it in as much fetishistic detail as he could. He'd been old enough to understand that he ought to check for scorpions, old enough to grasp that it would be very bad to be stung, but at the age of five, he hadn't acquired the tedious adult discipline of checking every time. Still, when his foot contacted the scorpion, and the sting sank in, there had been a moment of delicious clarity, a calm hiatus in which he understood precisely what had happened, precisely what was about to happen, and that there was nothing in the universe that could stop it. It had come like a wind-whipped fire, spreading up his leg, through the branching intricacy of his nervous system a his first real understanding that he even had a nervous system.

But there it was, traced out in writhing, luminous glory, like a ship's rigging wreathed in St Elmo's fire. In that moment he could have drawn an anatomical map of himself.

It was a memory he had tried his best not to return to, but perhaps because of that it remained raw, the edges still sharp, the colours and sensations bright. He felt his chest tighten, his heart rate increase, sweat prickle his back. In the neural scan of his brain, he saw the fear response light up.

Matilda was feeling it now as well. In response she issued a threat rumble, and Geoffrey took a step back as he sensed her growing agitation. His eyes were wide open now. He let go of the memory, forced it back into the mental box where he had kept it all these years. Enough for now; he'd gone sufficiently far to prove his point. It was unfortunate that the first demonstration of that had involved fear, but he'd needed something capable of producing an unambiguous signal. Matilda's neural pattern was settling down now; he hoped that she would not be troubled by what had happened.

He was about to suspend the link when, without warning, Eunice appeared. She was standing to his right, watching proceedings with her hands behind her back.

Geoffrey was about to admonish the figment a she had as good as promised not to appear without his direct invocation a when it occurred to him that, since Matilda was sharing his sensorium, she should also be aware of Eunice.

He voked to suspend the link, but the damage had been done. Matilda had seen something there, something entirely novel, something she had never encountered before in her life. The figment would have been disturbing enough in its own right, popping into existence like that a elephants moved through a world of solid persistence, of dusty ground, rocks and weather-shaped trees a but the figment would also have been made visible, ghostly and translucent, by virtue of the five-per-cent threshold. Elephants didn't have to believe in ghosts to find an apparition profoundly upsetting.

Matilda certainly didn't like it. He had primed her by stimulating the fear response, but he doubted she would have taken the figment well under any circumstances. She alternated trumpeting with threat rumbles and began backing away from the spot where the figment had appeared. Geoffrey might have broken the link, but Matilda wasn't going to let it slip that easily.

*You stupid fool!' he shouted. *I told you not to show up like that.'

*What's wrong with them? Why are they behaving like that?'

*Because she was in my head when you appeared. She saw you, Eunice. And she doesn't know how to deal with it.'

*How could she have seen me, Geoffrey?'

*Get out of here,' he snapped. *Leave. Now. Before I rip you out of my head with a rock.'

*I came to tell you something important. I've just learned the news from my counterpart up on the Moon. Your sister's on her way to Mars.'

*What?'

*Mars,' the construct repeated. *There's a Maersk Intersolar swiftship leaving tomorrow and the Pans have bought her a slot aboard it. That's all.'

The figment vanished, leaving him alone with the elephants.

Matilda might have been the only elephant neurally linked to Geoffrey, but it hadn't taken more than a couple of seconds for her agitation to communicate itself to the others. They had seen nothing, but when the matriarch alerted them that there was a problem, they took her at her word. Geoffrey couldn't see their eyes, but their postures told him that they were directing their attention to the same patch of ground where Eunice had appeared. There was no guessing what they thought Matilda might have seen or sensed there, but they were very clearly not taking any chances.

He thought of opening the link again, and doing his best to project calming reassurance . . . but with his mind in its present state, that was about the worst thing he could have tried.

Mars. What was Sunday playing at, after what she'd promised him?

No rash decisions.

He held up his hands. *I'm sorry, Matilda. There's nothing wrong, but I don't expect you to understand that now. And it was my fault.' He began to back up, barely giving a thought to what might be behind him in the darkness. *I think it's best if I leave you alone now, let you sort this out on your own. I'm truly sorry.'

She trumpeted at him then, an answering blast that he could not help but interpret as fury. He did not doubt that it was directed at him. He, after all, was the only alien presence in this environment. And if she grasped that the figment was in some sense unreal, then it was also the case that she had been made to look foolish, jumping at something that wasn't there, in the presence of the rest of the herd. She was matriarch, but only until the next female rose to challenge her.

He left the elephants to their grumbling, still feeling Matilda's disgruntlement even as he risked turning his back on her. He found his way to the Cessna, letting the aug light his path, and it was only when he was aloft that his hands stopped shaking. He had, he realised, left his bag down by the waterhole, along with the drawings: he'd forgotten it when the figment appeared.

Under other circumstances he might have circled down and retrieved it. Not tonight, though.

He'd done enough damage as it was.

CHAPTER TEN.

Sunday was just wondering what the time was in Africa a or, to be precise, at the household a when her brother placed a ching request. A coincidence like that should have left her reeling, but she'd long since learned to take such things in her stride.

She went to a leafy corner of the departure lounge, while Jitendra wandered over to poke at one of the maintenance bots, which was locked in some kind of pathological behaviour loop.

*Just thinking of calling you,' she told her brother as his figment popped into reality.

After the usual two-and-a-bit seconds of time lag he answered, *Good, I'm very glad to hear it.'

She studied his reaction. *You don't sound overjoyed, Geoffrey. Have I done something wrong?'

*I'm not sure where to begin. You're on your way to Mars without telling me, despite everything we talked about, and all of a sudden I've got my grandmother inside my head.'

*You two have already made your acquaintance, then.'

*That's one way of putting it.'

*Look, I should probably have warned you, but . . . well, what are surprises if you can't spring them on people now and again? Besides, I thought it would be useful for the construct. She needs to see a bit more of the world, and I'm obviously not going to be much help in that regard. So I took the liberty.'

*You certainly did.'

*I thought you'd appreciate the gesture. She's a . . . very useful resource.'

*Good. Now you can tell me what you think you're doing. According to your tag you're already at the departure station.'

*We are. Jitendra and I are just about to board the swiftship.' They'd come up by surface-to-orbit liner, spent a couple of hours in the freefall and spun sections of the station, eaten a meal, drunk too much coffee and passed the final medical tests prior to cryosleep. *They'll put us under soon,' she went on. *Lights out until Phobos.'

*And where the hell did the money for this come from?'

*Plexus funds,' Sunday answered. *June Wing's paying for Jitendra to go and do field work for the R&D division.'

*I hear the Pans are paying your fare.'

*Yeah. They want an artist in the loop, someone who can communicate their big ideas to the wider public. Because I know the zookeepers, I sort of got the job. Or at least a try-out, to see how it goes. There are Pans on Mars a they've got some start-up venture going on there.'

*And none of this comes with strings.'

*Oh, a few. But I don't have to buy into the ideology; I just have to wear it for a while.'

*And how long are you going to be away?'

*Not less than ten weeks, even if I get right back on the ship as soon as we reach Mars. Which, obviously, isn't the idea. It'll probably be more like four months, realistically a the return trip will take longer, too. I'm not going all that way just to spend a few days down there, and if the Pans are footing the bill . . .' She halted. *You're all right with this, aren't you?'

*Like I have any choice.'

*It's only Mars. It's not like I'm going Trans-Neptunian.'

*There's a difference between you being on the Moon and . . . whatever it is, twenty light-minutes away.'

*I have to do this, Geoffrey. I'm thirty-five, and apart from a small coterie of admirers in the Zone, I'm virtually unknown. In two years I'll be older than Van Gogh was when he died! I can't live with that any longer: it's now or never. This opportunity's come up, and I have to take it. You understand, don't you? If it was something about elephants, and it meant that much to you-'

*Think I might have told you about it. Just in passing.'

It was a strange conversational dance they were engaged in. Geoffrey was rightly cross about her decision to go to Mars, but he was well aware of her real motivation, which had nothing to do with the Panspermian Initiative. On the faint chance that their conversation was being intercepted, though, he had to pretend that the whole thing was a massive shock, in no way related to the events in Pythagoras. And his questions about funding were perfectly sincere. Her own finances couldn't possibly stretch to this.

But they hadn't needed to. The right word to Chama and Gleb, and it hadn't been long before Truro put in another appearance. That took care of her ticket, even if it put her deeper into hock with the Pans. Jitendra, similarly, had ramped up his debt to June Wing.

*If I'd told you,' she said, *we'd have ended up having exactly this conversation, only with the possibility of you talking me out of it.'

*I'm not trying to be overprotective.' He paused. *Well, maybe just a little. But Mars is a long way away. Stuff happens there.'

*I'm not travelling alone, and I won't be getting up to any mischief.'

Apart, she thought, from the kind of mischief she and her brother already knew about.

*I know you meant well with the construct,' Geoffrey said, *but she got me into a world of trouble.'

*How so?'

*Managed to screw up one of my exchanges with Matilda. Spooked the whole clan, and now I'm going to have to go back and start rebuilding trust.'

*How . . .' Sunday started asking, because she could not imagine how the construct could possibly have played any role in Geoffrey's elephant studies. But her instincts told her to abort that line of enquiry. *If that's the case, then I'm sorry. Genuinely. It's my fault a I gave her enough volition to auto-invoke, based on your perceptual stimuli. Basically, if she sensed sufficient attentional focus, she was cued to appear.'

*Even when I'd told her not to?'

*She can be contrary like that. But you don't have to put up with her a I'll deactivate your copy. I can do it from here.'

*Wait,' Geoffrey said, letting out a sigh. *It's not that I mind having Eunice on tap. I just don't want her springing up like a jack-in-the-box and scaring me half to death. Can you just dial down that . . . volition, or whatever it was?'

Sunday smiled. *I'll assign the necessary changes before they put me under.'

*Thank you.'

*You're doing me a big favour with this, although I'm sure you know that.'

*Just as long as we're clear on one thing,' Geoffrey said. *I'll keep her until she drives me mad, or you get back from Mars. Whichever comes first.'

*I'll call you when I wake up. But be prepared for the time lag a we won't be able to ching, so that's going to feel . . . weird. Be like the days of steamships and telegrams.'

*All else fails, send a postcard.'

*I will. Meantime, give my regards to Memphis?'

*We're going out to the elephants tomorrow. We'll be able to have a good old chat.'

*Wish I could be there with you.'

Geoffrey smiled tightly. *Some other time.'

*Yes,' she said, nodding. *Some other time. Take care, brother.'

His response took longer than time lag could explain. *Take care, sister.'

Geoffrey closed the ching, saving her from having to do it.

CHAPTER ELEVEN.

He dropped into what was obviously a departure lounge, bright and tree-lined, shops and restaurants hewn out of something resembling white stone, all irregular windows, semicircular doorways and rounded roofs, the floor and ceiling curving away out of sight, people walking around with the bouncy-heeled gait that he immediately recognised as signifying something close to Lunar gravity.

He had no physical embodiment. All local proxies and golems were assigned, and would remain so for at least the next hour. Still, the figment body he'd been allocated would suffice for his needs. When he made to walk, there was a lag of three seconds before anything happened, and then his point of view was gliding forwards, ghost arms swinging purposefully as ghost feet slid frictionlessly against the floor. The body was slightly transparent, but that was merely a mnemonic aid, to remind him that he wasn't fully embodied and couldn't (for instance) intervene in a medical emergency, or prevent an accident or crime by force. The other people in the lounge would either see him as a fully realised figment, a spectral presence, a hovering, sprite-like nimbus a simply a point of view a or, depending on how they had configured their aug settings, not at all.

Walking with time lag was hard, but stopping was even worse. No harm could possibly come to Geoffrey or his environment, of course, and the ching was considerate enough to slow him down or adjust his trajectory before he appeared to run into obstacles, and therefore risked looking clumsy.

Other than that, it was disarmingly easy to forget there was any time lag at all. He could turn his head instantly, but that was because his *eyes' were only ever intercepting a tiny slice of the available visual field.

He wandered the lounge, completing a full circle of the centrifuge without seeing anything of the ship. Eventually he found his way out of the centrifuge, into a part of the station that wasn't rotating. The ching protocols permitted a form of air swimming, which was in fact far more efficient than would have been the case had he been embodied. He paddled his way to a window, incurving so that it faced the station's core, and there was his sister's swiftship, skewering the hollow cylinder from end to end.

Geoffrey looked at it for several minutes before it occurred to him to invoke Eunice.